


Chase The Night, Fear The Morning

by Scribo_Vivere



Category: Supernatural
Genre: Alcohol Withdrawal, Angry Castiel, Angry Dean, BAMF Castiel, BAMF Dean, Bitterness, Blasphemy, Blood, Blood and Gore, Canon-Typical Violence, Castiel in Denial, Character Death, Demon Blood Addiction, Demon Dean, Demon Dean Being an Asshole, Denial of Feelings, Dirty Thoughts, Hateful Dean, Heavy Angst, Hedonism, Hurt No Comfort, Hurt Sam, Mark of Cain, Minor Original Character(s), Multi, Non-Canonical Character Death, Original Character Death(s), Original Character(s), Ruthless Dean, Survivor Guilt, Temptation, Violent Thoughts
Language: English
Status: In-Progress
Published: 2015-08-23
Updated: 2016-09-30
Packaged: 2018-04-16 17:54:47
Rating: Mature
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 10
Words: 6,916
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4634715
Author URL: https://archiveofourown.org/users/Scribo_Vivere/pseuds/Scribo_Vivere
Summary: <blockquote class="userstuff">
              <p>Sam and Castiel believe that Dean has been cured from the effects of the Mark of Cain--or at least, Sam does; Castiel isn't so sure the hunter he calls comrade and brother is truly free of the evil both within and without. Nevertheless, the angel chooses to give the man the benefit of the doubt...and it may well cost all of them dearly.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

  * For [Zana_Zira](https://archiveofourown.org/users/Zana_Zira/gifts).
  * Inspired by [Putting the Dean in "Deanmon"](https://archiveofourown.org/works/2493392) by [Zana_Zira](https://archiveofourown.org/users/Zana_Zira/pseuds/Zana_Zira). 



> This is inspired by, and is a continuation of, the lovely fic "Putting the Dean in Deanmon" by the talented Zana_Zira, who was kind enough to allow me to keep going with her wonderfully gritty, frightening version of Deanmon. Multiple chapters are ahead and I work 40 hours a week, so please forgive any updates that take a bit to post!

Much to Dean's fury, however, Sam decided to announce the next day that Castiel would be joining them at the diner as a way to celebrate their success at "curing" him. Dean simply stood there for an instant, debating whether just ripping Sam's throat out with his bare hands would be worth the effort, but then just as quickly changed his mind.

_Bad idea to tip him off Dean's permanently AWOL,_ he thought, and his jaw twitched at Sam's concerned inquiry of, "Dean? Is everything all right?"

"Fine," he lied immediately, tone brusque and dismissive, and for once, he didn't have to pretend that he was pissed off.

It was just as well that Sam's back was already to his brother when Dean's eyes shifted to a cold, oily black in hatred.

**

"You don't seem to be interested in your steak and eggs."

Castiel's voice was soft, almost pitying, and Dean blinked furiously, resisting the urge to flash his true eyes. It was the third time in an hour that either Sam or Castiel had asked after his welfare, to varying degrees of sickening intensity. If this kept up, Dean was going to cause one hell of a bloodbath at the bustling establishment, his true self needing to be kept under wraps be damned.

However, the angel seemed to take the action as a sign of emotional distress, and Dean thanked every demonic god or goddess in existence. One thing he'd always been good at was playing the little feathered freak's emotions like a broken violin. He lowered his voice and eyes as he toyed with his fork.

"Sorry, Cas," he murmured, making sure to add a hint of his famous self-loathing to the words as he spoke. "I just feel so damn guilty about everything that's happened. I can't eat."

Across the table, Sam looked up from cutting his sausages, surprise on his face, which quickly morphed into sadness as Castiel's blue eyes grew pained. No doubt the two friggin' saps were amazed at how easily he'd opened up when it was usually akin to pulling teeth.

_Speaking of_ _pulling_ _things..._

Dean's fingers unconsciously clenched around the handle of his coffee cup, which suddenly let out an earsplitting crack and proceeded to send a river of scalding coffee into his plate and over his wrist.

"Shit! Dean, god--someone get me wet towels!" Sam yelled, and leapt up from the table to run for the nearest waitress who didn't have her hands full of a check, liquid, or food.

Instantly the people nearest him were shouting and pointing as they, too, attempted to help, and Dean's blood began to thrum in his ears as the Mark sang to him.

_Hungry...need to kill...too many around takehideslice **BUTCHER** \--_

"I'm so sorry!" A breathless, brown-eyed waitress with a well-endowed bosom that barely fit into her uniform rushed over with a stack of dampened bar mop towels, and for a moment Dean almost forgot how to play the part of an injured, helpless Dean, so demanding was the urge to murder in his head.

"Uh, yeah, that's..don't worry about it," he said feebly, making sure to keep the fingers of his other hand wrapped tightly around the "burn"--Castiel didn't need to see that he was already healed, or he'd be in a pile of shit so big he  _would_ have to end the lives of everyone involved, and very messily. "I'll just...go take care of this in the bathroom."

"Are you sure you're okay? I know it might be awkward, but I'd like to help." Her pretty young face was filled with horrified shock and concern, and Dean felt his stomach doing somersaults with the anticipation of a coming kill. "After all, I was the one who poured that coffee. I feel terrible the cup broke like that."

Dean forced down the wild urge to scream for joy at this unexpected development, instead rising slowly, noting the compassionate looks of both Sam and Castiel.

"It's okay, really. I have a strong grip. It's not your fault," he lied, and she smiled sheepishly.

"Come with me, and I'll make sure you're all patched up," she said gently, and Dean looked at Castiel as if asking for his approval. Castiel, of course, gave a grave nod, and Sam waved him off hurriedly.

"Go on, Dean, before that scars," he said anxiously.

Dean let the girl lead him to the men's room, and once they were out of sight of prying eyes, allowed a wolfish grin to slip free as his eyes flicked to coal.

 

 

 

 

 

 

 


	2. Much Madness Is Divinest Sense

**Summary for the Chapter:**

> Assent, and you are sane; demur, you're straightway dangerous, and handled with a chain.

**Notes for the Chapter:**

> Title and summary are excerpted from Emily Dickinson's magnificent poem of the same name as the title; I've always thought it fit Deanmon beautifully.
> 
>  
> 
> **Also, please note that while it says "chapter two", the first chapter is actually Zana_Zira's original work. This should be chapter three, and the one before should be chapter two, but I'm not able to fix the listing; please forgive me!**

Sam didn't seem to be worried, assuring Castiel in an undertone with a small, knowing chuckle that Dean was "probably thanking her in his typical way", but the angel was not convinced. Unbeknownst to the younger Winchester, he had been uneasy from the moment Dean's eyes returned to their shade of normal green in the bunker's dungeon. It was a heavy, cold feeling sitting in the pit of his stomach, and try as he might, Castiel could not shake it.

He was fully aware of the ritual steps needed to cure a demon, and while he knew Sam was more than competent to fulfill every one, he was also  _not_ unaware that the Mark of Cain was a formidable, and highly volatile, counterpart to Dean's soul, though the man had been doing his best to keep its effects hidden. If what he suspected was true--and Castiel prayed with every fiber of his being that it was not--both he and Sam were in serious danger.

"Let's go," came Dean's voice from his right, and Castiel looked up to see the hunter standing by their table with a weary look, wrist bandaged and slightly bloody. He was the picture of exhaustion and misery, and suddenly Castiel felt horrible guilt wash over him. How could he even begin to think that Dean was simply playing to their emotions and good graces? The man was nearly broken. To think less of him now, and to let on that he was harboring those thoughts, would destroy what little self-esteem, if any, Dean still held on to.

Still, the angel found as they left the diner that he put himself between Dean and Sam as they walked to the car.

**

Dean could have snarled aloud. The damn angel knew; he was certain of it. Those blue eyes had always been able to read him like a book, and there was no logical reason for the winged dick to move between him and his brother unless he'd caught on.

What had tipped him off? Dean mentally replayed the scene from the bathroom in his head. Quiet kill, check; girl off the radar, check; blood kept to a minimum, despite how badly it had hurt to not carve the simpering bitch up like a Thanksgiving turkey, check; body stashed in the dumpster out back and arranged to look like a suicide; check, check, check; why the **_fuck_**  was he keeping Castiel around when he could just tear his wings out inch by inch...

"Dean, we're home."

Sam's voice cut through his mental fantasies, and wordlessly Dean opened the passenger side door. Having Sam drive the Impala when the cheap piece of metal would be better off having him behind the wheel, and using it as a getaway car if need be, was making him lose a few extra marbles day by day. Still, if he wanted to plan this right, he'd need to keep his mouth shut and suffer.

"I'm going to bed."

Castiel peered at him as both he and Sam exited, the uneasy knot inside of him increasing fourfold, but said only, "At this moment? Are you unwell?"

Dean's eyes were averted as they entered the bunker and he headed for his bedroom, though it was more to protect himself as he felt the obsidian threatening to rise again. _Lie to Cas, round two._

"Of course I'm _unwell_. I just came off being a demon and to make things worse, I made an ass of myself at the diner. So yeah, I'm going to bed, and no, I don't need you to watch over me. Stay the hell out."

Both Castiel and Sam watched him go, and only when the sharp snick of his door being shut had echoed in the bunker did Sam blow out a breath, catching Castiel's eye apologetically.

"Um, sorry about that," he offered half-heartedly. "Dean's...not himself."

Castiel simply nodded, never taking his gaze off the hallway Dean had retreated down. After a moment, Sam murmured he was going to get a drink and slipped off to the library, leaving Castiel to repeat his words in his head.

_Dean's not himself._

Castiel prayed, once again, that neither of them would find out how true that statement possibly was.

 


	3. Imitation of Life, Baby

**Summary for the Chapter:**

> This is where the ghost hides; this is where the truth lies...

**Notes for the Chapter:**

> Title and summary taken from Rob Zombie's song "Ride", from his CD _Educated Horses_. Photo of Deanmon courtesy of: http://33.media.tumblr.com/b88e192c4fe81da6807dd675220fc772/tumblr_inline_niizcuLzVq1r8mm9e.gif

 

Sleep, Dean found in short order, did not welcome him with open arms.

His blood burned in his veins, so painful that he was reduced to a shuddering wreck on the mattress, his fingers clenched so tightly in the fabric that a ripping sound was soon heard. The single kill at the diner had done nothing to alleviate the cravings of the Mark, and only accentuated the driving need and relentless desire to _rip something to pieces_. And of course, both the miserable featherbrain and his moping brother were still in the way. Proving to be more of a problem, however, was Castiel. 

Even though he was a Knight of Hell and far more powerful than even Cain at this point, Dean wasn't an idiot. He knew that if Castiel wanted to eliminate him, he very well could. After all, he was a demon, and he'd seen enough of the angel's little palming trick to know that death by a furious, grief-stricken seraph wasn't a gentle way to go for his kind.

Another spasm of pain hit him, and Dean staggered up, violently crashing into the bathroom and managing to lean over the tub before he was dry-heaving, blood mixing with his saliva and turning the ceramic interior into a disturbing mosaic of mottled pink. His skin prickled with searing heat, and sweat filmed the hollow of his throat as his true eyes came to the fore.

This game of hide-and-seek, he realized with a howl of agony, was absolutely  **not working**.

**

The sound of his brother screaming in pain from halfway across the bunker made Sam lose his grip on the nearly-empty bottle of Jack Daniels he was using to forget their predicament, and it shattered at his feet as he stumbled out of the chair and ran down the long hallway, his heart in his throat. He'd heard Dean yell before, but not like this. This sounded like...

_Like a demon's roar,_ his brain supplied, and Sam pushed his legs faster. He nearly collided with Castiel's form as he barreled around the last corner.

"Cas, what the hell?" he snapped, breathless and driving away the alcoholic fog from his brain. "I need to get to my brother! Move!"

Castiel's voice was filled with cold anger, but also held an undeniable fear that Sam had never heard, and it froze him on the spot as much as the angel's words did.

"That is not your brother."

Stepping around Castiel, Sam lost the ability to breathe. In front of them stood Dean, his eyes the color of a starless night sky, chest heaving. He spoke in a low growl.

"I'm hungry, damn it."

 

 


	4. There's A Bad Moon Arisin'

**Summary for the Chapter:**

> I fear the end is comin' soon...

**Notes for the Chapter:**

> Chapter title and lyrics courtesy of Mourning Ritual's "Bad Moon Rising" cover from The Walking Dead. Deanmon gifs found on the web, if you recognize them as yours please claim credit in the comments!

"Dean," Castiel said quietly, "what has happened to you?"

Dean spat at him like a cat as the angel approached, and Castiel paused when the hunter let loose a low, rumbling growl from deep within his chest, a dire warning to stay away. He needed to feed the Mark, and Castiel knew he was highly volatile at this moment. Any sudden, wrong move would cause disaster.

"Dean?" Sam's small voice could be heard at Castiel's back, and Castiel found he had almost forgotten that the younger Winchester was still there. "I thought you were cured. I did everything to save you."

"Well, it didn't work," Dean hissed, and his body tightened like a coiled spring as Castiel moved barely a fraction of an inch. "I'm still all demon, and good fucking riddance to the childish creature I used to be."

"This is not your true form." Castiel's voice had risen in anger, and Dean immediately calmed, tilting his head slightly in a manner eerily reminiscent of Castiel's own.

"No?" he said softly. "You know what my soul went through in the Pit, Cas. You smelled the reek of sin, guilt and fury all over me. You really think that when I ascended, I was going to just give all that up to be weak?"

"I know what your your soul looks like, and it is not this disgusting manifestation," Castiel snapped, and used his angelic senses to see past the man's human face to what lay beneath.

And cried out in horror.

Under the beautiful countenance he had come to love and trust was a mask of bone, juxtaposed into evil so strong Castiel stumbled in grief. The green eyes he was used to seeing were now the color of rich oil, and curling ram's horns, blistered and blackened, jutted from his scalp. His skin was sallow, and his canines were sharp and wickedly stained with blood--whether his own or another's, Castiel found he did not want to know.

"Still think I'm human, Castiel?" Even Dean's voice was all wrong--a sibilant hiss, sounding like broken glass and rough as stone, yet filled with unholy glee. "I don't think I've seen you this horrified since we went to that whorehouse all those years ago."

Steadying himself, Castiel met Dean's coal eyes in contempt. 

"I will purge this evil from you," he said, but was dismayed that his voice trembled slightly. 

Dean heard it, and threw his head back, laughing wickedly. "Oh, you're afraid of  _me_ now? What a great turn of events," he chuckled.

"I'm not."

Dean's head snapped up, eyes narrowing in hatred as Sam approached slowly, hands held upright before him in a gesture of harmlessness.

"I want my brother back," he pleaded. "Come on, Dean, fight this." His lower lip quivered. "I can't do this without you," he whispered.

Dean's eyes cleared to green, and Castiel caught his breath. Could it be his sibling's love had done the trick?

"Sammy?" Dean's voice--his true voice--nearly brought Sam to his knees, and he went forward without hesitation and wrapped his arms around his big brother, burying his face in his shoulder. 

"Yeah, Dean, it's me."

Castiel had no time to cry out in warning before Dean snarled high and long, his eyes flicking back to coal in an instant, and sank his teeth into Sam's neck, blood curling out under his tongue.

 

 

 

 

**Notes for the Chapter:**

> I apologize for the long amount of time between updates! Life has been amazingly busy. Thank you all who have encouraged me to continue with this series!


	5. Counting Bodies Like Sheep

**Summary for the Chapter:**

> \--to the rhythm of the war drums...

**Notes for the Chapter:**

> Title and summary from the song by A Perfect Circle. I suggest listening to it as you read this chapter. I had it on repeat the entire time. ;) Deanmon photo off of the Internet; if it's yours please claim credit!

Castiel leapt forward and caught hold of Dean's waist, tugging with all his strength, and Sam yelped softly as his brother's teeth ripped harshly away from his skin. 

With a deafening roar, Dean spun on Castiel and backhanded him, sending the angel to the floor of the bunker in a heap. 

"Weren't you taught not to interrupt a man's meal, Castiel?" he hissed.

Sam backed away in a rush as Dean approached him again, hand to his bleeding neck and terror in his eyes. "Dean, don't--"

"Shut the  _fuck up_."

The bloodlust in Dean's expression was terrible to behold, and Castiel knew if he did not do something, Sam would not survive. He let loose his angel blade and quickly slit his wrist. It would heal later, if slowly.

Dean spun at the scent of fresh blood, and his obsidian eyes shone with lust and hunger.

"Playing with danger, are you?" he said softly, and walked toward the angel like a cat stalking a mouse.

"You will not kill Sam," Castiel replied, trying to still his thundering heart. "If the Mark wants blood, take mine."

Dean caught his arm in a tight grip. "Well then, since you're offering..."

Castiel's vision whited out for an instant as Dean's mouth latched onto his skin, and it took every ounce of angelic energy he possessed to remain on his feet as the hunter pulled mouthful after mouthful of life-giving fluid from his body. The pain of having something so dark and evil near him caused him to shudder.

After what seemed like an age, Dean broke away, his lips and teeth stained bright red, and roared in satisfaction, pinning Castiel to the spot where he stood with one look.

" _ **More**."_ **  
**

"Not this time, you demonic son of a bitch."

Dean screeched as Sam dumped an entire bottle of holy water down his back from behind, and Castiel placed the tip of his blade at Dean's throat as the demon reached for Sam in fury.

"Go," Castiel commanded, and Dean snarled again, eyes filled with malice and hatred before the bunker was suddenly empty but for the two of them. 

Sam shakily leaned against the wall. "We're in trouble," he quipped weakly, and Castiel waved a hand over the wound he bore, wincing slightly as the flesh began to knit together. It hurt, a sure sign that he was indeed losing some of his power around Dean.

"That is a gross understatement."

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

**Notes for the Chapter:**

> I fear this situation is only going to get worse, folks...


	6. John The Revelator

**Summary for the Chapter:**

> ...wrote the book of the Seven Seals.

**Notes for the Chapter:**

> Title and summary copyright Curtis Stigers (some of you may know him from the SOA soundtrack).

"What the hell are we going to do, Castiel?" Sam asked, leaning back in his chair at the kitchen table and downing half the bottle of Jack in one gulp, his hands trembling. "Dean's totally gone off the rails."

Castiel slowly sat opposite him, unwilling to voice what was so painfully obvious, that Dean was just _gone_. The man Castiel had once known and deeply loved was nothing more than an amalgam of hate, destruction, and unbridled lust.

_Lust._

Against his will, Castiel saw in his mind's eye Dean feeding from him, and though the image gave him a distinct case of fear and nausea at the recollection, he couldn't deny the heat that had swept through him when the Knight of Hell had been stalking him. It was a terrifying thing for him to admit that he still very much wanted Dean, because there _was_ no Dean anymore, only a demon that was, quite literally, Hell-bent on their misery and possible deaths.

The knowledge was enough to make Castiel want to weep.

"--because that's the only thing I can think of, and I know it sounds awful, but...Castiel, are you listening to me?"

Ashamed, Castiel simply shook his head. "Forgive me, Sam. I was not."

Sam's lower lip trembled. "No, I'm the one that should ask for forgiveness. I had the opportunity to turn Dean back into a human and I fucked it up. Now I don't know if there's anything of my brother even left in there." He swallowed hard. "But judging by the fact that he tried to eat us both, I'm guessing not."

Castiel sighed, running a hand over his face. "Dean's soul was always the brightest, even in Hell when I was sent to rescue him. Sam, when I looked at him, I could find none of that light. The only way I can describe it to you is for you to imagine a slick puddle of oil left on pavement during the night."

Sam paled. "Dean has no soul?"

"No, he has a soul. It is simply tainted, and we must find a way to return it to its former state." Even as he spoke the words, Castiel wondered who he was trying to convince: himself, Sam, or the both of them.

"That's what I was saying." Sam put the bottle aside, his expression troubled. "Dean wants you. It's obvious."

Castiel began to object, but Sam held up a hand. "Don't try to deny it, Castiel. Even when Dean was still human, I saw the way you two looked at each other. Now that he's a...a demon, it's worse. Especially because he has no control over what he needs and wants. He'll do anything to get it." His eyes flickered away for a moment, then refocused on Castiel.

"We might have to use you to lure Dean out. I don't want to, but I can't think of anything else that would make him come close enough so we can fix him."

Castiel hesitated. "Sam, this is an extremely dangerous plan."

"I know it is." Sam's eyes were heavy and sad. "We could both die. But Castiel, if I don't get my brother back..."

He didn't finish, but Castiel knew he did not have to. The consequences of losing Dean to the Mark of Cain forever were thoughts that neither one of them had the strength to think about.

"I will do it," Castiel said softly.

Sam quickly stood. "Do you know where he is, or should I summon him?"

It was clear the mere thought of seeing his brother so soon after their first encounter frightened Sam, and thus, Castiel shook his head, rising as well, a sad smile on his lips.

"I have always known where Dean is. My Grace bound him to me when I raised him. Whether he feels it or not at the moment, we are and will forever be one."

Before Sam could even begin to think of a reply to that casual bombshell, Castiel had vanished.

#

Dean slid the Blade from the throat of the office manager and smiled, then slowly licked it clean, savoring every drop. It abated his hunger, but the real blood he wanted...now that was nowhere to be found. The taste of Castiel's life had fueled him with greater strength and power, and he wanted **more.**

 _Actually_ , Dean thought with a dark chuckle, _I just want that angel. Maybe up against the wall, or spread out beneath me while I maul him and make him taste all the pleasures of the flesh he's been missing..._

Absentmindedly, Dean realized he was already half-hard just from thinking about the prospect. To curb the burning ache in his groin, at least for the moment, he decided to begin carving random runes and sigils into every part of the dead man's body, starting with his eyes.

"Dean."

At the voice, Dean paused, and then slowly rose from his crouch by the victim's body, turning to face the one creature he'd been hoping to see, his lips turning up in a smirk as his eyes flashed to coal.

"Well, hey there Cas. Glad you could join the party."

 

 

 

 

**Notes for the Chapter:**

> I am so very sorry this update has taken so long! Thank you all for your patience!


	7. Burn Them Bridges Down

**Summary for the Chapter:**

> Burn them, burn them to the ground.

**Notes for the Chapter:**

> Title and summary from a poem I wrote and have yet to post concerning Deanmon and Castiel.

Castiel stood his ground as Dean approached, his skin prickling--with desire or loathing, he could not tell which. The demon paused when he was but a foot away, and blatantly stared the angel up and down. Castiel fought the un-heavenly urge to squirm.

"Why are you here, angel?" Dean chuckled, beginning to circle him now. "Sam try his little trick about wanting someone to bring his brother home? I can tell you right now, I'm not going anywhere near the bunker or that freak with the bottle of holy water." For just an instant, Dean's expression turned dark and foreboding. 

"I still have burns on my spine."

"The blessed water was used to keep you from destroying your brother," Castiel said quietly. "Or me."

Now, Dean laughed outright, but since he was standing directly behind Castiel, his mouth was at his ear, and the sound came out like a dirty, breathy whisper.

"Oh, I think I've already destroyed you well and good. You can hardly keep it in your pants for me."

At that, Castiel wrenched away, his eyes narrowing. "I have no intention of...of..." He realized in horror he could not even say the words, but then, Dean was one step ahead of him for that.

"No intention of what? Fucking me?" The demon grinned, and Castiel bared his teeth in hatred.

"I will never succumb to your disgusting desires."

"Oh, but they're not just mine, Cas." Dean leaned casually against a filing cabinet, making no move to hide his now-full arousal. "I know what you dream about. What you yearn for." His voice dropped at least three octaves, and his eyes turned once again to coal. 

"What you need."

Castiel swallowed hard. "I refuse to--"

In a flash, Dean was upon him, bending him backwards over the desk, hand at his throat. Castiel's heart thundered wildly. Would he now meet his end?

But Dean had nothing of the sort in mind. Instead, he murmured, "Refuse to do this?" 

Castiel had no time to think before the demon's lips were upon his own, and all coherency left him. 

If Dean the man and hunter had been efficient at kissing, then Dean the demon and Knight of Hell was  _glorious._ He used his mouth and tongue as a weapon, deadly and leaving no hope for anything but surrender.

And surrender Castiel did, taking two fistfuls of Dean's shirt and pulling him squarely down on top of him, their legs tangling together. Dean let out a low, rumbling, satisfied growl deep within his chest and caught Castiel by the hips, in one movement pushing him further up onto the piece of furniture and simultaneously allowing his legs to drop open. 

When Dean leaned hard into him, his erection pressing deliciously against Castiel's own, the angel could only tighten his grip and wrap his thighs in a vise-like grip around Dean's own, the blood in his veins turned to molten fire.

Snarling, Dean kissed him more deeply, and the sudden sting upon his tongue made Castiel start before he realized he could taste copper in his mouth. Instantly, Dean's own tongue was there, curling around his own and lapping up the blood.

Desperately needing friction suddenly, Castiel raised his hips, and it sent Dean into a wild frenzy.

Before he knew it, the angel was invaded by Dean's cock, and he gasped at the intrusion, the pain almost unbearable. Dean pounded into him roughly, snapping and growling like a wounded animal the entire time, sweat painting the hollow of his throat in a damp sheen within the dim light of the office.

Castiel let out a high cry as Dean suddenly reached around his back, and...and  _how did he know..._

"I wasn't born yesterday, Cas," Dean breathed heavily. "I research."

The rough hands alternately stroking, tugging, and massaging his wings was more than Castiel could bear, and he groaned loudly, feeling the slick mating oils begin to flow freely from the glands hidden deep within his feathers. Dean leaned down to bite at the junction between shoulder and neck, and the sudden twist of both his fingers and his hips left Castiel whimpering, dampness gathering on his lashes as he gave his essence to the creature that, even now, he loved.

Dean let loose a claiming roar and spilled his seed into Castiel, capturing his lips again until Castiel found he simply could not breathe.

Trembling and loose-limbed, Castiel winced when Dean pulled out, zipping him up roughly before stepping away, hair disheveled and expression the very picture of devious debauchery. 

"Still think you're above me, Cas?" he asked, chest heaving.

On wobbly legs, Castiel stood, managing to make it only a few feet before he collapsed into a leather chair, his nerves singing and his heart only now beginning to slow. When he looked up again, Dean was gone.

Not a minute later, Sam crashed through the door, startling Castiel.

"I got the news from another hunter," he said in a rush. "They said Dean was here attacking someone, and I knew you were going to meet him and I thought you might need help, so I--"

Sam stopped, his eyes taking in the scene before him: the state of Castiel, the wet spots upon the desk, the weary expression Castiel wore, and said sorrowfully, "Castiel, you didn't. Tell me you didn't."

Castiel closed his eyes and did not answer. Everything, it seemed, had just become very, very complicated.

 

 

 

 

 

**Notes for the Chapter:**

> And well. *wipes brow* That was...unexpected.


	8. That I Did Always Love, I Bring Thee Proof

**Summary for the Chapter:**

> The way to love anything is to realize that it might be lost.  
> \- Gilbert K. Chesterton

**Notes for the Chapter:**

> Title copyright Emily Dickinson.

"How could you have sex with him, Castiel?" Sam demanded. "You know what he is."

"It wasn't planned," Castiel said wearily. "He...overpowered me." The angel neglected to mention that was only half the truth. Sam did not need to know that he had yearned for the connection like the moon yearned for the night. There was no telling what the hunter would think...or then do.

Sam, as he had suspected, however, wasn't buying it. He folded his arms and stared hard at Castiel until he spoke, his voice quiet.

"I cannot help but love him still, Sam."

At that, Sam seemed to crumble, and hung his head.

"I know, Castiel. But you can't let him get under your skin. It's what he wants." The words sounded difficult even to Sam's own ears, and Castiel sighed.

"What then am I meant to do? I can't simply..." But the sentence was left unfinished.

"Kill him?" Sam asked softly. "I don't want to either, but that means we have to find a way to stop him, or cure him. One or the other."

Castiel looked away, unable to say that even he wasn't certain there was a path to curing the Knight. What the younger Winchester had tried before was the only method Castiel knew, and that had obviously been a failure. What else they could try was a mystery even to the angel, and they were running out of time.

*

Sam pushed back from the table in the bunker and ran his hands through his hair roughly. He'd been poring over books, scrolls, and manuscripts for hours, and they'd yielded nothing. Not a single word was mentioned about how to cure a demon save for what he had already tried. It seemed there was no other alternative.

But then, Sam thought bitterly, the Men of Letters had never had to deal with curing a Knight of Hell, ever.

Utterly despondent, he put his head in his hands. Only by the grace of God, if He still existed and actually cared, would Dean survive.

_Survive..._

The word flitted through Sam's mind again, and suddenly, he pulled a thick tome towards him, flipping pages gingerly, yet hurriedly, remembering something he had seen but skimmed past. Now, he wondered how he could have been so foolish.

Finding it, Sam read it again, slowly. The text, he realized belatedly, was in Turkish, and for that he'd need Castiel.

"How can I be of assistance?"

Sam jumped, not having heard Castiel enter the room. To his surprise, the angel held a steaming mug of coffee in his hands, and his trench-coat was gone, reducing him to only his white dress shirt, whose sleeves were rolled to the elbows. He looked tired and sad.

 "There's something here I can't read. Can you translate? I'm pretty sure it's a way to help Dean," Sam said.

Castiel peered over his shoulder, and after a moment, he spoke, the slightly gutteral yet beautiful language flowing from his lips.

_" Ancak tek kanamaya eder ve ruh birer yaşamak zorundadır..._Sam, do you know what this means?"

Sam was surprised to find that Castiel's voice was slightly agitated, and he said cautiously, "It's good news, right?"

" 'By the hand one shall bleed, and from the soul one shall live.' This is deep, penetrating spirit magick, Sam, magick even I am not sure is safe to use," Castiel said, his brow creased with anxiety.

"But what does the spell mean?" Sam asked, Castiel's worry beginning to rub off on him. "If we can use it to cure Dean--"

"This is magick that has not been used since the days of the Nephilim." Castiel seemed to struggle to explain.

"When the fallen angels took mates in the days of Noah, this was the ritual they used. It is a binding spell, and one that is very old, and very powerful. The ingredients are..."

Castiel stopped, and Sam said, rather impatiently, "They're what, Castiel? Whatever they are, I'm willing to go any lengths to get them."

Castiel's eyes had flicked away, and it was only after a few long moments that he looked at Sam again, deep worry in his eyes.

"My Grace, Sam. I would need to tear out my Grace."

 

 

 

**Notes for the Chapter:**

> Another update! Again, I apologize for the wait.


	9. Between the Spirit and the Dust

**Summary for the Chapter:**

> \--I have another trust.

**Notes for the Chapter:**

> Title and summary c. Emily Dickinson.

 

"Tear out your Grace?" Sam's voice was slightly louder than he had intended it to be. "That will kill you, won't it?"

Castiel seemed very old suddenly, and he spoke quietly. "No, I don't believe so. The Nephilim were able to do such a thing and remain on the earth. I assume I will become human."

Sam stared at Castiel as though he'd suddenly sprouted horns, eyes slightly wide. "Human? Is that really what you want?"

Castiel stiffened. "What I _want_ is of little consequence at this point, Sam. Dean needs all of the help we can give him, and I--"

"You're willing to just sacrifice everything for him? I know you care, Castiel, but this is a really big move. And we don't even know if you'll survive it." Sam's brow was creased now, too. "Even if it does work, you'll be locked out of Heaven forever. What about the other angels? Your family? Your duties?"

Castiel sat, giving the man a bitter smile. "I have never been on close terms with Heaven, Sam, and as for my duties, I have repeatedly neglected them in lieu of watching over Dean. It hardly matters now."

"Well..." Sam seemed at a loss. "What else do we need for the ritual? An angel's Grace seems pretty powerful in and of itself."

"For one, we will need Dean. Preferably restrained," Castiel added as an afterthought. "The spell will not be pleasant for him, either. It causes immense pain to both parties."

"Whoa, wait," Sam shook his head. " 'Immense pain'? I don't like the sound of that, Castiel."

Castiel sighed. "Dean is powerful now, Sam, and weakened as I will be, he could easily cause disaster. The room where the cure was tried will do."

"Do I have to feed him human blood again?" Sam seemed to cringe at the prospect, no doubt remembering the last time they had tried such a thing, but Castiel said, "No. All I will need you to do is restrain him. I will take care of the rest."

Sam was silent for a few moments. "Castiel, will you really live through this?"

The angel's own silence was answer enough for Sam.

*

Dean strolled through the bunker carelessly, unbelieving that his brother and the feathery moron had been suicidal enough to invite him back. Didn't they know what he was?

He chuckled to himself, calling out mockingly, "Oh Sammy, big brother's home."

There was no reply, and Dean's eyes darkened as he saw the open door toward the basement. They were going to try to feed him humanity again? Oh, what killjoys they both were. Obviously, they hadn't learned their lesson from the first time. Well, if they wanted him to play along, he would.

The bunker's basement was dim, and there was still no sign of either Castiel or Sam. Feeling his insides claw and twist with the Mark's hunger and with rage, Dean was about to turn back when he saw a shadow flit across the back of the room. It wasn't hard to place the familiar shape.

"Sam, it's not nice to play hide and seek," Dean growled, and stepped forward.

Immediately he was immobilized, and looked down at his feet in disgust to see the devil's trap outlined in red paint. He snorted derisively.

"We tried this with Cain, Sammy. Didn't work too well, if I remember correctly. This ring isn't going to hold me forever." Dean added with a snarl, "Start thinking or start running." The Mark had reached its boiling point in his blood, and he could feel the invisible barrier beginning to crack slightly around him.

"The days of running are long over."

Dean turned his head, a sinister smile crossing his lips. "Cas, you really should have known better. You're the first one I'm going to gut."

From his agreed place of waiting across the room, Sam saw the way Castiel swayed slightly, a sheen of sweat coating his face, and prayed that the ritual would work. Dean seemed to notice too, because he laughed.

"Don't tell me," he chuckled. "You've done some sort of ancient soul magick to try to bring me back from the edge." There was more mockery in his tone now. "Mixing your blood with mine isn't gonna make me want to stop carving everyone up like Thanksgiving turkeys, you know."

Castiel spoke, somewhat breathlessly. "You shall not touch another. I swear it."

"Then you'd better hurry up with your _plan_ ," Dean snapped, "because I'm hungry."

Slightly slower than usual--though still faster than Sam's eyes could place--Castiel caught hold of Dean's shirt and dragged him forward over the Devil's Trap, breaking the circle. At once Dean swung out with his fist, which connected with Castiel's face with a horrifying sound. Sam winced, hating being helpless, but stayed where he was. He had been warned that to interfere with such a ritual could result in his death.

"You stupid little angel," Dean hissed, hauling Castiel up from the floor. "Did you really think this would work?"

"I had hoped," Castiel croaked around a faceful of blood, and slammed his palms into Dean's chest, beginning to cry out in an ancient, unknown tongue.

Dean's scream bounced off the bunker walls, and he tried frantically to get away. But something--Sam knew not what--was holding him there in front of Castiel, and as Sam looked closer, he could see tendrils of bluish-white surrounding the both of them.

_Castiel's grace,_ he thought.

The angel's voice reached a fever pitch, so painful to hear that Sam had to cover his ears. He had been warned of this too, and squeezed his eyes shut as brilliant light exploded all around him, worse than an angel dying and brighter than the sun at close range, Dean's final scream echoing in his mind.

 

 

 

 

 

**Notes for the Chapter:**

> I'm so sorry for the eternally long update! I've had medical issues and have been unable to continue for some time.


	10. The Eye of the Sage, and the Heart of the Brave, are Hidden and Lost in the Depths of the Grave

**Summary for the Chapter:**

> When you are dining with a demon, you have got to have a long spoon. - Navjot Singh Sidhu

"Is he going to be okay?"

Castiel leaned against the bunker's basement wall wearily, trying to stave off the beginnings of an unbearable migraine, and sighed.

"I honestly don't know, Sam. I barely survived the ritual, and now I am mortal. I've given everything to save your brother. The rest is up to him."

Chewing worriedly on his bottom lip, Sam looked into the chamber--the same one where he'd first begun the process of trying to turn Dean human again--and stared at his sibling's still form, head bowed over his chest. He knew that if Castiel's ritual hadn't worked, there was only one route left. And he didn't want to think about it.

Castiel swayed on his feet suddenly, and Sam turned, steadying him.

"You should get some rest, Cas. I can handle watching Dean."

But the former angel shook his head. "No, Sam. I began this, and I will see it to the end."

The firm tone of his voice let the younger man know there would be no sense in arguing with him. He laid a brief hand on Castiel's shoulder, and then ventured back down the hall.

*

The fog began to clear from Dean's mind, and he slowly raised his head, willing his eyes to focus. The coal orbs landed on Castiel, and it was only when Dean went to move forward that he realized he was restrained in a chair--not with rope this time, but with thick chains etched with Enochian runes. His voice was hoarse when he spoke.

"This shit again, Cas?"

Castiel's eyes were wary as he watched Dean. There was no outward sign of the aggression the demon had shown earlier, but Castiel found he did not wish to take any chances. His body ached from the strain of the ritual and Dean's attack.

"You are still a demon, Dean," he finally said. "Your brother and I cannot risk your escape again."

Dean's eyes slid shut, and he said softly, "Don't think there's any risk of that, Cas. I can barely move as it is, even without these chains."

Castiel peered closely at the man. Something was different. His eyes had not shifted to their vibrant green, but there was no sign of the violent creature he had once been. What was going on?

*

Sam sat on his bed with pictures in his hands, staring alternately at the lively photos: him and Dean as youngsters with their mother, a rare shot of a smiling John showing Dean how to throw a baseball that Sam could only assume had been taken by another hunter; himself, the day he had graduated Stanford, cut out of a newspaper article that Dean must have saved all these years. It made Sam's heart ache to realize that the brother, friend, and man he knew would never be any of those things again.

"Sam. Your brother is exhibiting strange signs."

Sam jumped at Castiel's voice, turning quickly at his words. "What do you mean? Is he all right?"

Castiel looked helpless. "I don't know. It seems the ritual has worked, but his eyes..his eyes exhibit the opposite."

Sam's heart skipped a beat, and he asked the question even though he wasn't sure he wanted to know the answer. "What are you saying, Castiel?"

The other man paused, and then came the words that Sam had been hoping he would not hear.

"I don't...it appears your brother is half-mortal, half-demon."

 

 

 

**Notes for the Chapter:**

> Thank you all so much for being so patient in waiting for another chapter! I hope you approve of it! Title copyright William Knox, from his poem "Mortality".


End file.
